DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce

Point of Contact

DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce843-740-1200coastal.info@noaa.gov

Associated Resources

Lidar QA/QC Report

Originator

DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce

Publisher

DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce

Date(s)

publication: 2003-02-27

Data Presentation Form:

Digital image

Dataset Progress Status

Complete

Data Update Frequency:

Not planned

Supplemental Information:

The tide patterns of Willapa Bay required that the project area be divided into three
sections, and LiDAR flights had to be flown in an East/West orientation to capture
the low, low tide conditions. As the tidal waters moved throughout the Bay, flights
were completed according to tide data provided by the University of California - Davis
(Evolution & Ecology Dept.). Flights were completed during all acceptable periods
- day or night.

Purpose:

The elevation data will be used to investigate the impacts of invasive species on
the local ecology.

Use Limitations

These data depict the elevations at the time of the survey and are only accurate for
that time. Users should be aware that
temporal changes may have occurred since this data set was collected and some parts
of this data may no longer represent actual surface
conditions. Users should not use this data for critical applications without a full
awareness of its limitations. Any conclusions drawn
from analysis of this information are not the responsibility of NOAA or any of its
partners. These data are NOT to be used for navigational purposes.

Time Period:

2002-03-26 to 2002-04-24

Spatial Reference System:

urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters

Spatial Bounding Box Coordinates:

N: 46.7609

S: 46.3479

E: -123.616

W: -124.277

Spatial Coverage Map:

Themes

Bathymetry/Topography

LiDAR

laser

beach

invasive species

spartina alterniflora

DEM

erosion

Places

US

Washington

Willapa Bay

Use Constraints

No constraint information available

Fees

Fee information not available.

Lineage Statement

Lineage statement not available.

Processor

Spencer B. Gross, Inc

DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce

The raw LiDAR data was checked for complete coverage following each mission and at
the end of the flights. The data was pre-processed using SBG software to correctly
establish the position of each x-y-z point. The data was checked again for completeness
and conformance to specifications by comparisons to ground surveyed points. The LiDAR
data was post-processed using a customized version of Terrasolid software and bare
earth terrain models were developed.

The post-processed data from Spencer B. Gross were delivered in Washington State Plane
(South) projection referenced to NAD27 with vertical elevations in US survey feet
referenced to NGVD29. The data were converted to geographic coordinates using General
Cartographic Transformation Program software developed by the United States Geological
Survey. The data were then transformed to NAD83 using NADCON grids from the National
Geodetic Survey (NGS). A final datum transformation was performed to convert vertical
elevations referenced to NGVD29 to NAVD88 using NGS VERTCON grids. A comparison of
the LiDAR data to a ground truth data set indciated a 0.137m bias, which was removed.
The data were then converted to a binary format and loaded into the LiDAR Data Retrieval
Tool (LDART) database.

The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp
transfer from the NOAA Coastal Services Center. The data are
currently being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/.
The data can be used to re-populate the system. The data are archived in LAS
or LAZ format. The LAS format is an industry standard for LiDAR data developed by
the American Society of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless
compressed version of LAS developed by Martin Isenburg (http://www.laszip.org/). The
data are exclusively in geographic coordinates (either NAD83 or ITRF94). The data
are referenced vertically to the ellipsoid (either GRS80 or ITRF94), allowing for
the ability to apply the most up to date geoid model when transforming to orthometric
heights.